WO2014086097A1

WO2014086097A1 - Passive power factor correction and alternating-direct current conversion device and power factor correction circuit operation method

Info

Publication number: WO2014086097A1
Application number: PCT/CN2013/001414
Authority: WO
Inventors: 潘晴财; 陈伯彦; 洪大胜
Original assignee: 东林科技股份有限公司
Priority date: 2012-12-06
Filing date: 2013-11-19
Publication date: 2014-06-12
Also published as: JP2016502838A; CN103856077A; JP6026008B2; EP2930831A4; CN103856077B; EP2930831A1

Abstract

A passive power factor correction and alternating-direct current conversion device and a power factor correction circuit operation method. The conversion device contains a rectification circuit (20) and a power factor correction circuit (30). An input port (202) of the rectification circuit is electrically connected to an alternating current power supply (S), and the power factor correction circuit contains a first inductor (L1), a second inductor (L2), a first capacitor (C1), a second capacitor (C2), a first diode (D2) and a second diode (D1). One end of the first inductor is electrically connected to a positive end of an output port (204) of the rectification circuit, and the other end thereof is electrically connected to a negative end of the output port via two series paths in parallel connection with each other; one of the series paths is composed of the first capacitor and the second diode, and the other series path is composed of the second inductor and the second capacitor. The second capacitor supplies power for a parallel load. The first diode is connected across the two series paths. The conversion device controls the input current of the alternating current power supply, effectively improving the power factor.

Description

Passive power factor correction AC/DC converter and power factor correction circuit operation method

Technical field

The present invention relates to a passive power factor correction circuit, and more particularly to a passive power factor correction AC/DC converter and a power factor correction circuit. Background technique

The AC/DC converter is used to convert the received AC power into DC power and output. FIG. 1 shows a conventional AC/DC converter device including a rectifier circuit 10 and an output capacitor c. The rectifier circuit 10 converts an AC power source S into a DC power source, and the output capacitor C is connected across the output terminal of the rectifier circuit 10. And the output capacitor C is for the parallel load R. When the AC/DC converter is in operation, the input voltage v _{in of} the AC power source S is different from the input current ^, resulting in a power factor and a serious total harmonic distortion. In addition, the output capacitor C is charged only when the voltage of the DC power source is higher than the voltage of the output capacitor C. Therefore, the charging time of the output capacitor C is shortened, and the conduction time of the diode in the rectifier circuit 10 is also caused. This is shortened, and the peak value of the on-current is increased, resulting _in waveform distortion and power factor reduction of the input current i _in . In addition to wasting energy, power factor reduction increases the power supply of power companies and is an unnecessary burden. Accordingly, the AC/DC converter having the power factor correction circuit is born.

The power factor correction circuit conventionally used for the AC/DC converter can be classified into active type and passive type. The active power factor correction circuit uses an active switching element to control the input current. The advantage is that the power factor can reach 0.99 or more, the current "the total wave distortion is less than 10%, the input voltage range is wide, the output voltage is stable, and is not affected. The influence of output power variation. However, the active power factor correction circuit requires the use of additional active switching elements, which has the disadvantages of high manufacturing cost, high electromagnetic noise and low durability. The traditional passive power factor correction circuit is the inductor L, which is the inductor. L is connected in series to the input end of the rectifier circuit 10 of the AC/DC converter (refer to FIG. 2), which has the advantages of simple and durable structure and no electromagnetic interference caused by active switching elements. Since the inductor L requires a large silicon steel sheet inductor, silicon steel The volume of the chip inductor increases with the output power and the rated input voltage decreases, and the power factor is up to 75%, which cannot meet the requirements of today's use. If the power factor of the AC/DC converter with passive power factor correction circuit can be improved, Can replace the high cost AC/DC with active power factor correction circuit In addition, in order to reduce the ripple of the output voltage on the load R, the output capacitor C described above must use a high-capacitance electrolytic capacitor, and the electrolytic capacitor is liable to leak out of the electrolyte due to prolonged heating. This leads to a shortened life of the circuit.

In view of this, the main object of the present invention is to provide a passive power factor correction AC-DC conversion. The operation device of the changing device and the power factor correcting circuit can effectively improve the power factor of the AC/DC converting device, and does not need to use an electrolytic capacitor, thereby effectively improving the service life of the AC/DC converting device.

The object of the present invention is achieved by the following technical solutions. The passive power factor correction AC/DC converter provided by the present invention comprises a rectifier circuit and a power factor correction circuit. The rectifier circuit has an input port and an output port, and the input port is electrically connected to an AC power source, and the rectifier circuit converts the AC power into a DC power source and outputs the output from the output port; the power factor correction circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, a first diode and a second diode, wherein:

One end of the first inductor is electrically connected to the positive end of the output port of the rectifier circuit, and the other end is electrically connected to two serial paths connected in parallel, wherein a serial path includes the first capacitor and the second diode, the first One end of the capacitor is electrically connected to the first inductor, the other end of the first capacitor is electrically connected to the cathode of the second diode, and the anode of the second diode is electrically connected to the ground end of the output port of the rectifier circuit; The other of the second inductors is electrically connected to the first inductor, and the other end of the second inductor is electrically connected to one end of the second capacitor, and the second capacitor is electrically connected to the second inductor. One end is electrically connected to the ground end of the output port of the rectifier circuit; the second capacitor is connected to the parallel load; the anode of the first diode is electrically connected between the first capacitor and the cathode of the second diode, The cathode of the first diode is electrically connected between the second inductor and the second capacitor.

The object of the present invention can also be further realized by the following technical measures.

The passive power factor correction AC/DC converter of the foregoing, wherein the inductance of the second inductor is greater than or equal to ten times the inductance of the first inductor.

The aforementioned passive power factor correction AC/DC converter device, wherein the second capacitor is a non-electrolytic capacitor.

The object of the present invention is also achieved by the following technical solutions. According to the above concept, the present invention further provides an operation method of the power factor correction circuit, which comprises the following steps:

A. receiving a DC power output by the rectifier circuit;

B. turning on the second diode, and outputting energy to the load by the first capacitor and the DC power source until the second diode is turned off;

C. outputting energy from the DC power source to the load until the first diode is turned on;

D. charging the first capacitor by the DC power source and outputting energy to the load until the first diode is turned off;

E. outputting energy from the DC power source to the load until the second diode is turned on;

F. Repeat steps B through F until the AC power input to the rectifier circuit is stopped. The object of the present invention can also be further achieved by the following technical measures.

In the foregoing method for operating the power factor correction circuit, in the step B, when the voltage of the first capacitor is greater than the sum of the voltage of the first inductor and the voltage of the second capacitor, the second diode is turned on until The voltage of the first capacitor is less than the voltage of the first inductor and the voltage of the second capacitor At the sum, the second diode is turned off.

The operation method of the power factor correction circuit, wherein, in the step C, when the voltage of the DC power source is greater than a voltage of the first inductor, a voltage of the first capacitor, and a voltage of the second capacitor, the first two The pole tube is turned on.

In the foregoing method for operating the power factor correction circuit, in the step D, when the voltage of the DC power source is less than the voltage of the first inductor, the voltage of the first capacitor, and the voltage of the second capacitor, the first two The pole tube is cut off.

In the foregoing method for operating the power factor correction circuit, in the step E, when the voltage of the first capacitor is greater than the sum of the voltage of the first inductor and the voltage of the second capacitor, the second diode is turned on.

According to the above technical solution, the passive power factor correction AC/DC conversion device and the power factor correction circuit operation method of the present invention have at least the following advantages and beneficial effects: thereby, the passive power factor correction AC/DC conversion device and its power factor correction The operation method of the circuit can increase the on-time of the diode in the rectifier circuit to control the input current of the AC power source, thereby effectively improving the power factor.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a circuit diagram of a conventional AC/DC converter;

2 is a conventional AC/DC converter with a passive power factor correction circuit;

3 is a passive power factor correction AC/DC converter device according to a preferred embodiment of the present invention;

4 is an equivalent circuit of the preferred embodiment of the present invention in a first state;

Figure 5 is an equivalent circuit of the preferred embodiment of the present invention in a second state;

6 is an equivalent circuit of the preferred embodiment of the present invention in a third state;

Figure 7 is an equivalent circuit of the preferred embodiment of the present invention in a fourth state;

FIG. 8 is a waveform diagram of a passive power factor correction AC/DC converter according to a preferred embodiment of the present invention. The best way to achieve your invention

In order to further illustrate the technical means and efficacy of the present invention for achieving the intended purpose of the invention, a passive power-correcting AC-DC converter and power factor correction circuit according to the present invention will be described below with reference to the accompanying drawings and preferred embodiments. The specific implementation method, structure, characteristics and efficacy of the action method are described in detail later.

FIG. 3 shows a passive power factor correction AC/DC converter device according to a preferred embodiment of the present invention, including a rectifier circuit 20 and a power factor correction circuit 30, wherein: The rectifier circuit 20 in this embodiment is a full-wave bridge rectifier having an input port 202 and an output port 204. The input port 202 is electrically connected to an AC power source S, and the AC power source S provides an input voltage V _in and an input. The current is _in to the rectifier circuit 20. In the embodiment, the AC power source S is a power supply provided by the power company, but not limited thereto, the utility power can also be stepped down or boosted via a transformer and electrically connected to the power supply. Enter port 202. After the AC power source S is rectified by the rectifier circuit 20, a DC power supply of twice the frequency is output from the output port.

The power factor correction circuit 30 includes a first inductor L1, a second inductor L2, a first capacitor Cl, a second capacitor C2, a first diode D1 and a second diode D2, wherein:

One end of the first inductor L1 is electrically connected to the positive end of the output port 204 of the rectifier circuit 20, and the other end is electrically connected to two serial paths connected in parallel, wherein a serial path includes the first capacitor C1 and the second diode D2, the first capacitor C1 of the embodiment is a polar capacitor, the anode of the first capacitor is electrically connected to the first inductor L1, the cathode of the second diode D2 is electrically connected to the cathode of the second diode D2, and the anode of the second diode D2 Electrically connecting the grounding end of the output port 204 of the rectifier circuit 20; the other series path includes the second inductor L2 and the second capacitor C2, the second inductor L2 is electrically connected to the first inductor L1, the second The other end of the inductor L2 is electrically connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is electrically connected to the ground end of the output port 204 of the rectifier circuit 20. The anode of the first diode D1 is electrically connected between the cathode of the first capacitor C1 and the cathode of the second diode D2. The cathode of the first diode D1 is electrically connected between the second inductor L2 and the second capacitor C2. A load R is connected in parallel across the second capacitor C2. In practice, the first capacitor C1 can also use a non-polar capacitor.

In the above circuit architecture, the operation method of the power factor correction circuit 30 is as follows: In each half cycle of the AC power source S (ie, each cycle of the DC power source), the power factor correction circuit 30 receives the The DC power output from the rectifier circuit 20 sequentially generates four different states, which are defined as a first state, a second state, a third state, and a fourth state. Wherein: when the voltage of the first capacitor C1 is greater than the sum of the voltage of the first inductor L1 and the voltage of the second capacitor C2, the second diode D2 is turned on to generate an on current i _D2 , the function The correction circuit 30 is in the first state, and its equivalent circuit is as shown in FIG. At this time, the first capacitor C1 releases energy to the second capacitor C2 and the second inductor L2, and the DC power source charges the second inductor L2 and the second capacitor C2 through the first inductor L1 and outputs energy to the The load R produces an output voltage V. The first state ends until the second diode D2 is turned off (ie, the voltage of the first capacitor C1 is less than the sum of the voltage of the first inductor L1 and the voltage of the second capacitor C2). In the first state, the first inductor L1 and the first capacitor C1 form a resonant circuit for reducing harmonic components of the input current i _in of the alternating current power source S.

When the voltage of the first capacitor C1 is less than the sum of the voltage of the first inductor L1 and the voltage of the second capacitor C2, the second diode D2 is turned off, and the power factor correction circuit 30 is in the second state, The equivalent circuit is shown in Figure 5. At this time, the DC power source passes the first inductor L1 to the second inductor L2 and the second capacitor C2 charge and output energy to the load R until the first diode D1 is turned on (ie, the voltage of the DC power source is greater than the voltage of the first inductor L1, the voltage of the first capacitor C1 The second state ends with the sum of the voltages of the second capacitor C2.

When the voltage of the DC power source is greater than the voltage of the first inductor L1, the voltage of the first capacitor C1 and the voltage of the second capacitor C2, the first diode D1 is turned on to generate an on current i _D1 The power factor correction circuit 30 is in the third state, and its equivalent circuit is as shown in FIG. 6. At this time, the DC power source charges the first capacitor C1, the second inductor L2, and the second capacitor C2 through the first inductor L1 and outputs energy to the load R until the first diode D1 is turned off (ie, The voltage of the DC power source is less than the voltage of the first inductor L1, the sum of the voltage of the first capacitor C1 and the voltage of the second capacitor C2, and the third state ends.

When the voltage of the DC power source is less than the voltage of the first inductor L1, the voltage of the first capacitor C1, and the voltage of the second capacitor C2, the first diode D1 is turned off, and the power factor correction circuit 30 is In the fourth state, the equivalent circuit is as shown in FIG. At this time, the DC power source charges the second inductor L2 and the second capacitor C2 through the first inductor L1 and outputs energy to the load R until the second diode D2 is turned on (ie, the first inductor L1) The sum of the voltage and the voltage of the second capacitor C2 is smaller than the voltage of the first capacitor C1. When the fourth state ends, the power factor correction circuit 30 enters the AC power source S and repeats the first state to the fourth half cycle. State, until the AC power S input to the rectifier circuit 20 is stopped.

FIG. 8 shows the input voltage V _in , the input current i _in , and the output voltage V of the above-described passive power factor correction AC/DC converter. The waveform of the on current of the first diode D1 and the on current i _D2 of the second diode D2. The load R is an example of a 100 ohm resistor. The first inductor L1 is 55 mH, the second inductor L2 is 550 mH, the first capacitor C1 is 10 μF, and the second capacitor C2 is 10 F. The input voltage V _in of the AC power source S is a sine wave of ll OVrms. It can be seen from FIG. 8 that the input current has been corrected to a waveform close to a sine wave, and the power factor of the passive power factor correction AC/DC converter is 0.959, which is effectively improved compared with the conventional passive power factor correction circuit. Power factor. In addition, the resonant circuit formed by the first inductor L1 and the first capacitor C1 can also effectively reduce the harmonic component of the input current i _in the AC power source S.

In the above, the first inductor L1 and the first capacitor C1 form a resonant circuit, and the on-time of the diode in the rectifier circuit 20 can be increased to control the input current i _{in of} the alternating current power source S. The resonant circuit formed by the first capacitor C1 and the first diode D1, the second diode D2, the second inductor L2, and the second capacitor C2 can reduce the output voltage V output to the load R. . The ripples and the effect of increasing the power factor of the AC power source S. Preferably, the inductance of the second inductor L2 is greater than or equal to ten times the inductance of the first inductor L1, and the charging and discharging time can be effectively controlled to adjust the first state, the second state, and The third state and the duration of the fourth state. In addition, the second inductor L2 has the functions of energy storage and filtering, and can provide energy to the load R and suppress the chopping of the current of the load R, whereby the second capacitor C2 can adopt a non-electrolytic capacitor ( Such as Ceramic capacitors or tantalum capacitors replace traditional electrolytic capacitors, thereby extending the life of the circuit.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention. The skilled person can make some modifications or modifications to the equivalent embodiments by using the above-disclosed technical contents without departing from the technical scope of the present invention, but without departing from the technical solution of the present invention, according to the present invention. Technical simplifications Any simple modifications, equivalent changes and modifications made to the above embodiments are still within the scope of the technical solutions of the present invention.

Claims

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A passive power factor correction AC/DC converter device, comprising: a rectifier circuit having an input port and an output port, wherein the input port is electrically connected to an AC power source, and the rectifier circuit converts the AC power source into a DC power source And outputting from the output port; and the power factor correction circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, a first diode and a second diode, wherein:

2. The passive power factor correction AC/DC converter of claim 1, wherein the inductance of the second inductor is greater than or equal to ten times the inductance of the first inductor.

3. The passive power factor correction AC/DC converter of claim 1, wherein the second capacitor is a non-electrolytic capacitor.

A method of operating a power factor correction circuit according to claim 1, characterized in that it comprises the following steps:

A. receiving a DC power output by the rectifier circuit;

B. conducting the second diode, and outputting energy to the load by the first capacitor and the DC power source until the second diode is turned off;

F. Repeat steps B through E until the AC power input to the rectifier circuit is stopped.

The method for operating a power factor correction circuit according to claim 4, wherein in the step B, when the voltage of the first capacitor is greater than the sum of the voltage of the first inductor and the voltage of the second capacitor, Passing the second diode, the second diode is turned off until the voltage of the first capacitor is less than the sum of the voltage of the first inductor and the voltage of the second capacitor.

The method for operating a power factor correction circuit according to claim 4, wherein in step C, the voltage of the DC power source is greater than a voltage of the first inductor, a voltage of the first capacitor, and the When the voltage of the second capacitor is summed, the first diode is turned on.

The method according to claim 4, wherein in the step D, the voltage of the DC power source is less than the voltage of the first inductor, the voltage of the first capacitor, and the second capacitor. The first diode is turned off when the voltage is summed.

The method according to claim 4, wherein in the step E, when the voltage of the first capacitor is greater than the sum of the voltage of the first inductor and the voltage of the second capacitor, The second diode is turned on.